As sound recording devices that collect and record external sounds, video cameras, digital cameras with a moving image capturing function, IC recorders, and the like are known. When such devices are operated, there are cases in which a pulsed operation sound generated from the main body of the devices is incorporated into recorded sounds.
For example, an imaging device equipped with a moving image capturing function collects external sounds around the device using a microphone and records the sounds together with a moving image when the moving image is captured. During the capturing of the moving image, a pulsed operation sound such as a zoom driving sound, a diaphragm driving sound, an auto-focus driving sound, a pressing sound of an operation button, or the like is generated in the housing of the imaging device. Particularly, when an operation of a driving device (a zoom motor, a diaphragm mechanism, a focus motor, or the like) that drives an imaging optical system starts or ends, a pulsed mechanical driving sound such as a “click” made when, for example, a motor engages with a gear is generated.
If such a pulsed operation sound is incorporated into or recorded as a noise on an external sound that a user desires to record, it is quite unpleasant. For this reason, it is necessary for a sound recording device to provide quietness or noise removal in order to reduce such a pulsed operation sound generated during recording.
As methods for reducing a pulsed mechanical driving sound, several methods have been proposed. For example, Patent Literature 1 proposes that in order to lower a reduction processing load to bear when a mechanical driving sound generated from a driving device is to be reduced, the reduction process is executed according to transmission of a driving signal for controlling the driving device. In addition, Patent Literature 2 proposes that input audio data corresponding to a period in which a loud noise is generated from a lens driving unit is interpolated with audio data pieces generated before and after the period based on a driving signal (control signal) for controlling the lens driving unit.